Residential solar power is becoming more like a box lunch than a seven-course gourmet meal.

A number of companies are taking advantage of technical advances, notably microinverters, to make buying a handful of solar panels, rather than a roof full, a viable option. That doesn't mean that everyone can install their own electric panels, but it can lower the cost of entry for solar.

"Nothing could be more timely in a down economy than to do the right thing in a way so that it doesn't kill the budget," he said. "You can start small and add more over time if you desire."

Green Ray Solar's SunSine AC Module, expected for availability in the fall, is one of a growing number of solar photovoltaic panels that take advantage of microinverters. It's a technology that has been pursued for years, but the reliability and efficiency have improved in the past few years.

Traditionally, solar panels are tied into a device called an inverter, which converts the direct current from panels into household alternating current. Strung together, several panels produce enough voltage to run an inverter which, sized for a rooftop array, is roughly as big as a computer monitor.

A microinverter brings that DC-to-AC function onto each individual panel. Proponents say the technology simplifies installation and improves panel performance. For example, shading on one panel will not affect the output of other panels connected to it, as happens with panels connected to a centralized inverter.

A full-size grid-tied solar array with about 15 or 20 panels can cost anywhere between $25,000 and $40,000 upfront depending on the size. AC panels are not cheaper, but proponents say the modularity makes it easier to install a few panels, and then later connect more to the existing set.

More flexibility
James Cormican took the small-steps approach to solar at his parents' home. Working with an electrician, he put five panels onto their garage, which was the only space with good sun available to them, for well under $10,000.

The advances in solar technologies in just the past couple of years give solar designers more flexibility to fit panels onto tighter spaces, he said. Whereas a full-size solar array will typically have a capacity of two kilowatts and higher, Cormican's system is rated at one kilowatt, which is about enough to run a few power-hungry appliances.

"Of course there are economies of scale when you have many panels installed, but the argument that you can't have a system with one or two solar modules is not true anymore," said Cormican, who is an instructor at the AltE Store, which sells alternative energy gear to consumers and installers. He said the AltE Store is seeing more interest and business for smaller solar systems.

In addition to panels equipped with microinverters, thin-film solar panels put out a higher voltage, which gives people more flexibility in choosing inverters, he said. In Cormican's case, the panels put out enough voltage to be tied into a traditional inverter.

Although the output and cost will vary depending on location, a one-kilowatt system will put out roughly 1,000 kilowatt-hours a year, and the installation cost is roughly $6 per watt, he said. Average electricity consumption in the U.S. is about 11,000 kilowatt-hours a year. Until 2016, solar installations receive a 30 percent federal tax credit, and there are often state incentives as well.

Cormican warned against people thinking that they can install panels themselves if they don't have the qualifications of an electrician or solar installer. Although regulations and building codes vary by state, there are serious safety issues related to both grid-tied systems and solar systems with batteries. It might be difficult to find an installer willing to take on small jobs, but a do-it-yourselfer could possibly share some of the work with a pro, such as installing panel racking.

"If you can find an installer who is willing to work with you and let you do the parts that you are legally allowed to do--anything that doesn't have to do with electrical work--then that can reduce the cost," he said.

Plug and play?
The solar industry has been on a multiyear quest to lower the cost of electricity from solar with higher manufacturing volume and more efficient solar cells.

But because about half of the cost of a solar PV system is tied up in installation, a number of companies are trying to cut the installation cost, called the "balance of system" in industry parlance.

Similarly, Ready Solar offers a "Solar in the Box" kit designed for quick installation. Another company, Armageddon Energy, by the end of this year hopes to release the Solar Clover, which is made up of several small, hexagon-shaped mini-solar panels. The hope is to have solar installs done in a few hours and as easy as buying a kitchen appliance.

Earlier this month, Seattle-area start-up Clarian Technologies got a lot of media attention for its Sunfish, a do-it-yourself solar system designed for consumers to install themselves. Promised for next spring, it would include one or three panels, a microinverter that connects into a home power outlet, and a controller at the circuit board. As the company has not yet shown a product or gotten UL certification for safety, there is a good dose of skepticism among professional installers, said Cormican.

In addition to modularity, one of the big advantages of AC panels equipped with microinverters is that they can be individually monitored. The system from Green Ray Solar, for example, will include a solar panel from Sanyo equipped with a microprocessor to gather performance information and a microinverter. The kit, available through installers, will also have a gateway that connects to a home Internet connection, giving people access to solar data online.

"The information side of things is very rich territory," said Russell. "It's really revolutionary for the industry to have this kind of scrutiny."

About the author

Martin LaMonica is a senior writer covering green tech and cutting-edge technologies. He joined CNET in 2002 to cover enterprise IT and Web development and was previously executive editor of IT publication InfoWorld.
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